1. Field of the Invention
This invention relates to a wheel bearing assembly in which a hub spindle of a wheel hub to which a traveling wheel is attached, and a constant-velocity joint outer ring are interlinked so as to be capable of torque transmission, and to a method of manufacturing the bearing assembly.
2. Description of the Related Art
In this type of wheel bearing assembly, a device having a structure disclosed, for example, in Japanese Patent Application Publication No. 57-178903 (JP-A-57-178903) as related art 1, and Japanese Patent Application Publication No. 62-194903 (JP-A-62-194903) as related art 2. In such a device, as shown in FIG. 9, in order to connect a wheel hub 210 and a constant-velocity joint 250 so that torque can be transmitted, two splines 218 and 262, two splines 218 and 262 that mesh with each other to transmit torque between a wheel hub 210 and a constant-velocity joint outer ring 260 are formed on an inner end surface of a hub spindle 213 of the wheel hub 210, and an outer end surface of an end wall portion 261 of the constant-velocity joint outer ring 260. Besides, in order to link the hub spindle 213 of the wheel hub 210 and the constant-velocity joint outer ring 260 with each other, an internal thread 263 corresponding to an external threaded portion 273 of a link bolt 270 is formed in the end wall portion 261 of the constant-velocity joint outer ring 260, and a central hole 214 through which a shaft portion 272 of the link bolt 270 is inserted is formed in a central portion of the hub spindle 213. Then, with the two splines 218 and 262 meshed with other, the shaft portion 272 of the link bolt 270 is inserted through the central hole 214 from a vehicle outer side of the hub spindle 213, and the external threaded portion 273 of the shaft portion 272 is fastened to the internal thread 263 of the end wall portion 261 of the outer ring 260. Thus, the hub spindle 213 of the wheel hub 210 and the constant-velocity joint outer ring 260 are linked to each other.
Incidentally, as for the wheel bearing assembly having a structure as shown in FIG. 9, the operation of inserting the shaft portion 272 of the link bolt 270 through the central hole 214 from the vehicle outer side of the hub spindle 213, with the two splines 218 and 262 being in mesh, and of aligning a distal end of the external threaded portion 273 of the shaft portion 272 with the internal thread 263 of the end wall portion 261 of the outer ring 260 is troublesome, and a great amount of labor is needed in order to fasten the link bolt 270.